Irradiation-sensitive material adapted for development by aqueous developer solution



United States Patent Oflice 3,529,965 Patented Sept. 22, 1970 IRRADIATION-SENSITIVE MATERIAL ADAPTED FOR DEVELOPMENT BY AQUEOUS DEVELOPER SOLUTION Eduard Roell, Thalanderlstr. 5, Munich- Obermenzing, Germany No Drawing. Filed Aug. 5, 1966, Ser. No. 570,407 Claims priority, appliclgtigii 2Gtirmany, Aug. 10, 1965,

Int. Cl. cine 1/52 US. Cl. 96--91 4 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to light-sensitive material and more particularly to light-sensitive material based upon light-sensitive compounds such as diazo compounds and to a process of producing such a material.

Light-sensitive material which utilizes the light-sensitivity of diazo compounds for producing photographic pictures are prepared according to the following two basically different processes:

(a) Both the diazo compound and the coupling agent are applied to or incorporated into the picture carrier or support. Development after exposure is mainly carried out by means of gaseous ammonia.

(b) Only the diazo compound is applied to or incorporated into the picture carrier. After exposure, of said light-sensitive carrier or support, the picture is developed by a treatment with an aqueous solution which contains the coupling agent. In one embodiment of this process the diazo compound is directly incorporated into the picture carrier or support. In another embodiment thereof the diazo compound is incorporated into a separate layer which is applied to the picture carrier or support. To produce such separate layers, gelatin and other water-swellable substances such as polyvinyl alcohol, carboxy methyl cellulose, and others, have been suggested as layer-forming material. Polymers, which are soluble in organic solvents may also be used for this purpose.

Many attempts have been made to use this diazo process for cinematographic purposes, especially for producing film copies, because of its low costs and its simplicity in operation.

For instance, the diazo copying process has been used for cinematographic purposes by means of the so-called ozaphan film. In such a film the diazo compound is incorporated into the picture carrier or support itself. Due thereto it is necessary to keep the carrier or support extremely thin. This excludes the general usefulness of this type of film.

Heretofore, it was not possible to provide a picture carrier or support of a thickness and composition as it is conventionally used for cinematographic films such as, for instance, cellulose triacetate, for the diazo copying process. When coating such a support material with a light-sensitive layer containing the diazo compound and a binding agent, it was found that the resulting lightsensitive material has considerable disadvantages which render diflicult rational and inexpensive processing of the exposed film. Such disadvantages are:

(l) Layers containin the light-sensitive diazo compound and consisting of water-swellable colloids or polymers have a relatively low melting point when swollen and, therefore, will not permit processing with developers at a higher temperature.

(2) Layers made of substances which are soluble in organic solvents and which consequently have the character of lacquers, are not sufiiciently permeable to aqueous developer solutions. As a result thereof the developing time is prolonged to an extraordinary extent.

To carry out the diazo copying process economically, however, requires the use of a developing bath of high temperature because the speed of reaction is accelerated at a high temperature and, as a result thereof, the developing time is shortened. Furthermore, an especially inexpensive coupling agent, namely fl-naphthol, is sufficiently soluble in hot water only, i.e., in water of a temperature above C.

It is one object of the present invention to provide a light-sensitive material useful in cinematographic copying which material is free of the disadvantages of the heretofore known and used material.

Another object of the present. invention is to provide a simple and effective process of making such a light-sensitive material.

A further object of the present invention is to provide a process of using such a new and valuable light-sensitive copying material.

Other objects of the present invention and advantageous features thereof will become apparent as the description proceeds.

In principle, the light-sensitive material according to the present invention comprises a picture carrier or support provided with a light-sensitive layer which combines the good properties of gelatin, such as its high absorptive power for aqueous solutions, with those of lacquer coatings, such as their high mechanical strength properties, their insensitivity to high temperatures, and their shortened drying time. For this purpose a mixture of said two components is prepared and is used as binding agent for the light-sensitive compound, such as the diazo compound.

A mixture of gelatin and lacquer forming substances is prepared by using said lacquer-forming substances in the form of their aqueous dispersions. Suitable aqueous dispersions are, for instance, the commercial latex-like preparations.

According to the present invention the following components are mixed with each other in a suitable proportion in order to produce highly resistant layers, which permit rapid development at a high temperature:

(a) As the one component: Hydrophilic, water-soluble or at least water-swellable, film-forming colloids such as gelatin, polyvinyl alcohol, polyacrylate, polyvinyl pyrrolidone, carboxy methyl cellulose, and the like.

(b) As the other component: Hydrophobic, substantially water-insoluble materials serving as supporting framework for said hydrophilic colloids such as butadiene copolymers, or other copolymers with acrylonitrile, polyvinyl acetate, polyvinyl propionate, polyvinyl chloride and other lacquer-forming substances. These materials are-used in the form of their aqueous latex-like dispersions which are miscible with said hydrophilic colloids and, after drying, yield a film meeting the requirements of light-sensitive layers, namely transparency, homogeneous surface, castability.

The favorable effect of such mixtures of water-swellable colloids and latex-like dispersion of film-forming substances may be explained by the fact that the lacquerforming substance dispersed in the latex forms after drying, a solid supporting framework for the water-swellable colloid which is built into said framework. As a result thereof, the desired properties of the water-swellable colloid can be made use of without impairment of the properties of the resulting film while the lacquer framework protects the mechanically sensitive water-swellable colloid.

The mechanical strength properties and the perme ability for aqueous solutions of light-sensitive layers prepared from such mixtures is dependent upon the respective proportion of the components in the mixture. By selecting suitable proportions it is possible to adjust to the specific requirements in any desired manner the mechanical properties as well as the permeability of the layer to aqueous solutions and to control the speed of development.

Since the purpose of the present invention is primarily the production of an inexpensive material for making film copies, it is the preferred procedure to use diazo compounds as light-sensitive substances.

The layers composed according to the present invention as described hereinabove, may also be used as carrier or support for other light-sensitive materials such as light-sensitive silver, iron, chromium salts and the like light-sensitive inorganic and organic compounds, provided their properties are adapted to the desired purpose. In such instances it is also of advantage to use a layer or support which has the property of being mechanically resistant at a high bath temperature and thus of permitting very short developing times.

A further advantage of the layers according to the present invention which swell in aqueous solutions only to a slight extent, is to be seen in the fact that, in contrast to conventional gelatin layers, the drying process, after processing the light-sensitive material, is shortened considerably. The high mechanical resistance of the lightsensitive layers permits to remove most of the adhering water by mechanically wiping it off. The small amounts of water which are contained in the only slightly swollen layer are evaporated within a very short period of time, especially since the high temperature resistance of the layer permits drying at a very considerably higher temperture than heretofore possible with gelatin layers.

The following example serves to illustrate the present invention without, however, limiting the same thereto.

EXAMPLE A 20% aqueous solution of photographic grade gelatin is prepared (Solution A).

A latex containing a styrene-butadiene copolymer, as it is sold, for instance, as Latex GRS III by the firm B. F. Goodrich Chemical Co., is adjusted to a solids content by diluting it with water (Solution B).

An aqueous solution containing 10 g. of a light-sensitive diazo compound, for instance, the diazonium salt of p-amino diphenylamine, in 250 cc., i.e., a 4% solution of the diazo compound is prepared (Solution C).

250 cc. of Solution A, 250 cc. of Solution B, and 250 cc. of Solution C are processed at a temperature of about 35 C. to a homogeneous mixture. After filtration to eliminate impurities and air bubbles, the resulting filtered solution is cast upon a support of cellulose triacetate provided with the conventional subbing coating. Conventional emulsion casting machines are used for this purpose. After drying, a film of high mechanical strength at a processing temperature between 70 C. and 80 C. is obtained. Such a light-sensitive material, after exposure,

is developed within about one second and the total processing time, including drying, is about three minutes.

In place of the diazo compound used in the preceding example, there may be employed other light-sensitive diazo compounds, such as the 4-diazonium dialkyl anilines, N-acyl derivatives of mono-diazotized p-phenylene diamine, 4-diazonium-2,5-dialkoxy diphenyls, 4-diazonium-2,5-dialkoxy diphenyl sulfides, and others as they are conventionally used in light-sensitive materials of the diazo type.

Other light-sensitive compounds which have proved to be useful in the claimed light-sensitive material are, for instance, silver halogenides, and iron salts.

Compounds which are sensitive to other types of irradiation than to light, are, for instance, silver halogenides which are sensitive to X-rays and also to ultraviolet rays. They may also be used for the purpose of the present invention.

As stated above, there may be used as Water-swellable film-forming colloids, in place of gelatin, polyvinyl alcohol, carboxy methyl cellulose, and others.

Water insoluble polymers which are soluble in suitable organic solvents and which are useful as supporting framework for the water-swellable colloid are not only the styrene-butadiene polymer latex but also polyethylene, polypropylene, chlorinated rubber, alkyd resins.

As coupling agents there are used the known coupling agents such as all phenols capable of coupling with diazo compounds such as p-naphthol, phloroglucinol, resorcinol, either along or in mixture with each other.

The supporting layer may not only consist of cellulose acetate but also of other film-forming materials as they are known in photographic films.

The proportion of water-swellable material and waterinsoluble framework material used as carrier for the light-sensitive compound may be between about 1:0.2 and 1:4 and preferably between 120.3 and 120.7 depending upon the desired properties of the resulting lightsensitive material.

Of course, many changes and variations in the composition of the supporting picture carrier, the Water-swellable component and the substantially water-insoluble framework component of the light-sensitive layer, the diazo compound or other lightand irradiation-sensitive compound and the like may be made by those skilled in the art in accordance with the principles set forth herein and in the claims annexed hereto.

What is claimed is:

1. Irradiation-sensitive material adapted for development by aqueous developer solutions, said material consisting of a supporting water-insoluble film base and a layer sensitive to irradiation on said film base, said irradiation-sensitive layer consisting of an intimate mixture of (a) gelatin, and

(b) styrene-butadiene polymer latex, the proportion of gelatin to styrene-butadiene polymer latex being between about 1:0.2 and about 1:4, said irradiationsensitive layer having incorporated therein a lightsensitive diazonium compound.

2. The irradiation-sensitive material according to claim 1, wherein the proportion of gelatin to styrene-butadiene polymer latex is between about 110.3 and about 120.7.

3. An irradiation-sensitive casting solution for providing an irradiation-sensitive layer which, on casting upon a supporting film base, forms therewith an irradiation-sensitive material adapted for development by aqueous developer solutions, said casting solution consisting of an intimate mixture of (a) an aqueous gelatin solution,

(b) a styrene-butadiene polymer latex, and

(c) an aqueous solution of a light-sensitive diagouium compound, the proportion of said gelatin solution and said styrenebutadiene polymer latex being between about 1:0.2 and about 1:4.

6 4. The irradiation-sensitive casting solution according FOREIGN PATENTS to claim 3, wherein the proportion of gelatin to styrene- 667 2 7 6 C butadiene polymer latex is between about 1:03 and about 35 H9 3 anada' 1107- DONALD LEVY, Primary Examiner References Cited UNITED STATES PATENTS 3,301,679 1/1967 Halperin et a1 96-75 U.S.C1.X.R. 3,228,769 1/1966 Workman 96-49 88 5 M. B. WITTENBERG, Assistant Examiner 

